1. Field of the Invention
The present invention relates to a dry distillation and gasification typed incinerator configured to store a waste material and combust a part of the waste material to release a combustion heat to be used to distill the remainder of the waste material through dry distillation to generate a combustible gas.
2. Description of the Related Art
In recent years, there is a trend that more and more waste materials contain a lot of chlorines such as vinyl chlorine and the like in their ingredients. When they are incinerated by an incinerator, air pollutants such as nitrogen oxide (NOx), carbon monoxide (CO), dioxins and the like will be generated in the incinerator. Thus, certain environmental standards have been formulated to inhibit emission amounts of these air pollutants.
Particularly, in disposing a waste material by incineration, when the waste material containing chlorines is incinerated at a temperature around 250 to 350° C., the chlorines liberated from the waste material and carbon hydrides generated from the incomplete combustion of resin or the like undergoes a reaction catalyzed by heavy metals contained in the waste material to generate the dioxins.
It has been considered effective to prevent the emission of dioxins from being generated in the incineration disposal of a waste material by detaining the waste material for 2 seconds or more at a temperature of at least 800° C. to completely pyrolyze the generated dioxins.
As an incinerator for incinerating a waste material such as waste tires or the like while preventing the emission of dioxins, the applicants of the present application have disclosed a dry distillation and gasification typed incinerator which is provided with a dry distillation furnace configured to store the waste material and combust a part of the waste material to release a combustion heat to be used to distill the remainder of the waste material through dry distillation to generate a combustible gas, and a combustion furnace configured to completely combust the combustible gas introduced from the dry distillation furnace (for example, refer to JP Patent No. 4005770).
In the apparatus mentioned above, after the combustion furnace is warmed up by the combustion of other fuels to a temperature of at least 800° C. which is possible to pyrolyze the dioxins, the waste material is ignited to generate the combustible gas, the generated combustible gas and the other fuels are combusted together in the combustion furnace. If the combustion of the combustible gas only can maintain the temperature of the combustion furnace stably at a high temperature of more than 800° C., the combustion by the other fuels is terminated. Thereby, in a phase from the initiation of dry distillation of the waste material till the combustible gas in the combustion furnace is stabilized to continue the combustion spontaneously, the temperature of the combustion furnace is maintained at least at 800° C. to prevent the emission of dioxins.
However, in the apparatus mentioned above, the other fuels are required to be combusted before the combustible gas is able to continue the combustion stably and spontaneously. Thereby, there are such problems that it costs time to aid the combustion and the running cost of the apparatus is increased due to the fuels required for combustion aid.
Particularly, since the temperature of the combustible gas introduced into the combustion furnace is lower than the temperature (at least at 800° C.) of the combustion furnace maintained through the warming-up, it decreases the temperature of the combustion furnace, which is the main cause of the time required for combustion aid.